Glass-polishing apparatus



- 1927" H. K. HlTCHCOCK V GLASS POLISHING APPARATUS Filed Deb. e. 1924 2 Sheets-Sheet '1' oct- 4 v I 1927 H. K. HITCHCOCK v GLASS POLISHING APPARATUS 4 Filed Dec. 9. 1924 2 Sheets-Shet 2 v Patented Oct. 4, 1927.

UNITED [sTTs HAL ERT K. HITCHCQGK, or PITTSBURGH, PEnNsY vAnI Ass enoia rorrr'rsnunen J PLATE GLASS COMPANY, A conrongwron 01F: rnnlvsynvan e. 1

eLAss-ronrsmne irranarus. r,

Application filed December 9, 1924. Serial 1m 754,753.

The invention relates to glass polishing apparatus, and particularly to that known as the straight away operatlon, in which the glass sheets are carrled along a track or runway on a train of cars or tables, being first carr ed beneath a serles of grindmg machines, and then beneath a series of polishing machines. The polishing mach nes, preferably each comprise a runner v1 (in the form' of a spider) mounted on a spindle and driven by a motor, and carrying a plurality of polishing blocks or discs, each free to rotate upon its shaft and provided" with the usual felt. v

In operation, the tables carrying the glass sheets'are moved slowly beneath thes'eries of. runners, a mixture ofirouge and water being supplied't'o the glass to secure thedesired polishing effect. The friction of the felts upon the glass heats it toa very considerable 'degree, and in practice, it has'been found that there is a considerable amount of breakage during the polishingioperation.

Where the glass passes in this manner slowlybeneath an annular polishing runner,zit is' polished in a circular ringor band wh ch progresses gradually along the ribbon, and this action has the tendency to heat theglass in a series of rings or hands. The localized heating resulting'procluces serious strains in the glass, causing'a considerable'amount of breakage, the conditions encountered here being quite difierent than that present in the regulation plate glass polishing operation on a circular table, in whichop era-tion, any

area of the glass surface. remains but a fraction of a second under any r'unnerb'lock, so

that localized heating is avoided. I In addition to the localized heating in circular bands, it has alsobeen found that the glass,

ribbon is unequally heate'c'l in longitudinal bands located oneach side of its logitudinal center line. v p p I T My invention is designed to reduce the unequal heating, as above pointed out, preferably by applying a cooling'flow of air to the heated annular and longitudinal hands. This reduces the differences in temperature xis ing in he r b on o a poi here e v difference is insu ien to prc uce' a y breakage.- The 0 1 ng efiect mayalsc be producedby cooling the metal bees of the able f m beneath, butthis i vo v g ea e'jr me h nical d ffisulties tha the app iic iv and'eflicient, because of-the insulating'eifect i of the plaster intermediate the beds-of the tables andthe glass plates; Certain ein-" bodiments of the invention ,arefillustrated 1n the accompanylng' drawings wherein:

F lgure'l 1s a planv1ew: showing the application of the air cooling means to one of i a series of polishing'machines. Fig. 2*is a transverse section. on :the line IIII of Fig. I

1 Fig. ,3 is aside-elevation showing a poret1on of the serles of polishin machines to which the invention is app ied together i with the means for carrying the glass there beneath." Fig. 4- is a partial plan view similar to that of Fig. 1; but illustratingamodified' means for securing the application of the coollngflow of air to'the glassQ Fig.

5 is a. section on the line V V*of Fig. 4.

And Fig.- 6 is a' detail side elevation view of one of thenozzl'es employed in the con struction of Figs. 4' and 5.1-

The glass to be ground and polished isv preferably carried upon a series f t or tables 1, 2, 3, etc. above which are mount ed a series of polishing machines. As illus-' trated, thesei achines each comprise a run ner 4 carried by a spindle 5 and driven from is concerned, which has to do primarily with I the means-for keeping certain portions of the glass "fromfbeing over heatedby the polishing blocks, so that breakage occurs. I f

As shown in-"Figs. 1; and -2,"eafch runner consists of a casting made upof the annular portion 8 attached to the central'hub '9 by the electric motor -6 through the intermedii means of the ribs '10 and carryingth'e runner blocks/11; faced with the usual felts 12.1 The runner blocks are each provided with a I spindlelS extending through *a' bushing 14 and held by a pin 15 which permits the runner 'bloc'ks to move freelyin a vertical I direction with their'weight resting upon-the I glass'plate 16 therebeneath. The lowerend of'the" runner spindle 17' fits-into atapering socket in the hub .9 andis s'ecuredfin posi'-.

tion by means of a pin 18 egrtending trans vers'ely through the hub and spindle.

sunnding the huh 9 seatedup on v I I to 60V 1 the series of polishing runners, but this is preferablyaccomplished by the means illustrated in Fig. 2 and comprlsing rack bars 48 l the radial arms is an annular casting'19 I I divided into a plurality of upwardly opening compartments 21 to 29 by means of the r partitions 30. These-compartments are open 5 laterally and downwardly as "indicated in L i the pipes 44 and 45. The casting19 is also provided around its. peripheryv with a rouge trough146 to whichia mixture of rouge and .wateris supplied from a suitable pipe, not

thetable through small outlet passages 47 the, trough.

"extending downwardlyfrom the bottom of carrying theglass are moved slowly beneath the series of polishing machines, each'runner .being'driven from itsimotor as heretofore 'poi'n'tedout, and the glass upon the tables is subject to. 1. action thev'polishing to 'the' high degree of polish required. With the 7 arrangement illustrated, the polishing heating eflectis found to be greatest in the j sideportions of the sheet :in the areas marked ofzFi'g. 1, the central area tlyingbetween the linesA and B being-heatedto a less degree.

.:' and as a result the unequal expansion and contraction in the sheets causes a consider able percentage of breakage in .suchsheets. The application: of theair from the inani- ;folds f gand41- tends to equalizethe temperature throughout the'sheet as the. greater portion. of the air supplied from t the mani "foldssand "flowing down through-the pipes 31 to 39 is applied at the side portions of thev sheets, the compartments in the casting v 1 '19f lying ;adjacent the longitudinal center- 1 line. 05-0, of themachine being out of registry with the discharge nozzles42-and 43, so that {the cooling air supplied to the surface of j fthesheet, is applied at the sides of: the sheet toja greater extent than'to the central por-- 1 tion. By. this meansthe temperature of the glass sheet from one. side of the-table to the 7 other is maintained substantially uniform and breakage due to. unequal heating and consequent'unequal expansion is eliminated.

f. Any desired means Jmay be employed, for moving. the tables orcarsjforward beneath.

' secured along the bottoms. of' the cars or tables and'engaged by a spur gear-49 driven shownyan'd this mixture finds its way to In operat1on,the series of ears l, 2 and 3;

. V "blocks 11 thus gradually bringing, the glass 7 effect of the. blocks and consequently the p w between. the dottedlines A-A and .B+B

from the gear 50 carried by the drive shaft v 7 Figs. 4, 5 and 6 illustrate a'modifiedarrangement for securing the application Oi /2L cooling flow of air to the surface of the glassplates carried by the tables. In this construction the rotation of the runners is util ized to produce the desired flow of air. Here, as in the other v type of construction, the polishing blocks 52 are carried by spindles 53' extending through the annular rim 54 of the runner casting, such rim being preferably in the form of the T'section indicated in Fig, 5. Clamped' to this T section between eachpairof runnner blocksis a casta ing 55 carrying a nozzle 56, the lower portion of the casting being provided with a pair of lips 57 fitting-above and below the flange of the T sectionand secured in position by means of the set screw 58. The nozzle portion 56 tapers inwardly and extends downwardly as indicatedin Figs. 5 and 6 terminating in an outlet 59 just above the surface of the glass. The-rotation of the runner. in the. direction indicated by the arrow in Fig. 4 causes a flow of airinto the it I:

nozzle 56, and thenz'downwardly against the a surface of the glass, so that the glass is cooled throughout, the polishing operation.

This. cooling effect is I applied uniformly, throughout the circumference of the runner,

so tha t the'central portions of the sheet .7 which are not heated to as :great an extent by the polishing action of the blocks as .the

side portions, are cooled to the same extent; as such side portions, but the temperature of the sheetthroughoutv isreduced to such I an extent that any difference in temperature between the central portion of the sheet and I the side portions is substantially reduced,'as"

well as the temperatureof thecircular bands} heretofore referred 1 to, so that all breakage due to unequal expansion is practically;

eliminated. 1 V

What I claim is:"

- vl. In glasslpolishing apparsuzus, the com? bination with a" series of runners mounted for frfl tation and provided With a plurality.

of, polishing blocks,1neans for rotating the f V runners, and glass supporting -1neans mounted, for movement beneath the runners,

of means for artificially cooling-the side glass passing beneath the Y portions of v the runners 2. In glass polishing apparatus, the com of polishing block's, meansfor rotating the runners, and glasssupporting means mounted for movement beneath the runners, of means for applying acooling flow of air to the side portions of the glass passing vbeneath --t-he runners.

3.- In glass polishing apparatus, the "combination with a' series of runners mounted bination with a series of runners mo'unted for rotation and provided with a plurality fective by the rotation of the runners, fordriving the runners, and glass supportingmeans mounted for movement beneath the runners, of means for supplying a cooling flow of air downward upon the annular surfaces over which therunner blocks pass in their movement of rotation about the axes of the runners;

'4:- In glass polishing apparatus, the combination with a series of runners mounted for rotation and each provided with an annular series of polishing blocks, means fordriving the runners, a glass supporting means mounted for movement beneath the runners, of draft producing means made efsupplying a cooling flow of air downward upon the annular surfaces over whlch the runner blocks pass in their movement of rotation about the axes of the runners.

5 In glass polishing apparatus, the combination with a series of runners mounted.

for rotation, and each provided with an annular series of polishing blocks, means for driving the runners, a glass, supporting means mounted for movement beneath the runners, of draft producing means in the form of tubular members carried by the runners and facing in the direction of rotation of the runners for supplying a coolingflow of air downward upon the annular surfaces over which the runner blockspass in their movement of rotation aboutthe axes of the runners. y

In testimony whereof, I have hereunto subscribed my name this 21st day of Nov., 1924. c HALBERT K. HITCHCOCK. 

